Finally, Apple saves its customers from bringing home an underpowered iMac. The key improvement: all new iMac G5s now ship with 512MB of memory, twice the default amount in the original's rollout last year. Along with the memory upgrade, the new iMacs ship with Mac OS 10.4 Tiger. The high-end 20-inch LCD model (reviewed here) and the midrange 17-inch model also get a CPU clock speed jump, up to 2.0GHz from last year's 1.8GHz. Apple made other improvements to the graphics, the hard drive, and the SuperDrive. Prices for the two lower-end models remain the same at $1,299 and $1,499, while the 20-inch model sheds $100 to end up at $1,799. Apple even throws in AirPort and Bluetooth as standard features now. As with any all-in-one design, you sacrifice expandability, and the iMac G5 will never be a world-beater in terms of performance, but the updated specs give the gleaming iMac G5 more bite.

Apple left the iMac G5's lovely design untouched. As before, it's not just the cosmetic impact of the iPod-like white-plastic and Lucite case that's appealing, but also the functional value of the simple integrated stand, the nearly hidden optical drive slot, and the minimal cable fuss. The iMac G5 has perhaps the easiest setup procedure we've ever encountered in a desktop: heft it from the box, plug in the power, the keyboard, and the mouse; and turn it on. And thanks to the now-standard AirPort card, if you have a wireless network available, you're good to go right out of the box.

Internal expansion is limited to adding more RAM (an easy user upgrade), but most everything you would want for mainstream use is already included. External expansion options abound, and even if more cables would disturb the Zen-like form factor, at least you can minimize wire clutter, thanks to the included Bluetooth receiver. If you must add a wired component, you'll find all of the ports on the back of the system, keeping the Apple iMac G5's clean face free of beauty marks. Two FireWire 400 ports allow you to connect peripherals such as an external hard drive, an iSight camera, or an iPod, and there are two USB 2.0 ports on the iMac G5's case and two USB 1.1 ports on the included wired keyboard. You can also plug in headphones or digital audio out and connect your iMac G5 to a TV via the S-Video or composite outputs or even mirror the desktop image on an external display (a.k.a. screen spanning). The iMac G5 doesn't support screen spanning, but many have found success using the Screen Spanning Doctor hack.

As long as you don't require a living room-size display, you won't find the need to export video to another screen; the Apple iMac G5's 20-inch screen is surprisingly bright and responsive. Thanks to its wide-screen aspect, it can display two text pages side by side. DVDs look great, too. Plus, the system runs quietly, which aids movie enjoyment and general computing. Still, we wish the integrated stand allowed for height adjustments.

Apple has long negotiated a tricky balancing act in configuring the iMac; the company doesn't want to make it so powerful that it would cannibalize Power Mac sales, but nobody likes an underpowered computer. With this revision, Apple has moved the 20-inch iMac G5 more solidly into the performance camp, with the 2.0GHz PowerPC G5 processor; 512MB of RAM standard; a 128MB ATI Radeon 9600 graphics card; and a large 250GB, 7,200rpm hard drive. This isn't to say the iMac G5 doesn't offer compelling bang for the buck. At $100 less than the original 20-inch model, it also includes a double-layer 8X SuperDrive, the aforementioned AirPort Extreme wireless networking and Bluetooth 2.0 capabilities, a 56Kbps modem, a Gigabit Ethernet adapter, and surprisingly capable integrated speakers. Heck, the display alone could go for nearly half the price of the iMac G5. In fact, the 20-inch iMac G5 has a faster processor and bus, more memory, a larger hard drive, and a better video card than the base-model Power Mac G5 which, though $300 cheaper, doesn't come with a monitor.

What you give up is internal expansion and the ability to upgrade; you can't add PCI cards to the iMac G5 or replace the processor or the video card, which may be a concern for heavy Photoshop users and gamers. The iMac G5's ATI Radeon 9600 is an acceptable card for older games and general use, but it can't run Doom 3 in high-quality mode at a playable frame rate.

Compared to the 1.8GHz iMac G5 we reviewed last year, the 2.0GHz iMac G5 completed CNET Labs' Photoshop CS tests at a clip that was more than 30 percent faster. It took the iMac G5 more than twice as long to finish the test as it took the new dual 2.7GHz Power Mac G5, but the Power Mac has the two processors (each clocked higher), a faster frontside bus, eight times the memory, and a more powerful graphics card. The iMac G5 trailed the Power Mac G5 on our new iTunes test, but it was able to edge an Intel white box with a 3.73GHz Pentium 4 Extreme Edition processor. (We suspect iTunes runs more efficiently on the hardware on which it originated.) Lastly, on our new video-encoding test, the iMac couldn't keep pace with the high-end competition, which isn't exactly a fair comparison (to date we've tested only high-end systems, such as the dual-processor Power Mac, and dual-core Intel systems on this benchmark).